diff --git a/modules/sd_models.py b/modules/sd_models.py
index ce6e37f6a..b08a70b72 100644
--- a/modules/sd_models.py
+++ b/modules/sd_models.py
@@ -1475,8 +1475,9 @@ def reload_model_weights(sd_model=None, info: CheckpointInfo | None = None, op='
     loaded_ckpt = getattr(sd_model, 'sd_checkpoint_info', None) if sd_model is not None else None
     changed_checkpoint = loaded_ckpt is None or checkpoint_info is None or loaded_ckpt.filename != checkpoint_info.filename
     reset_unet = shared.opts.sd_unet not in (None, 'Default', 'None')
+    reset_unet_secondary = shared.opts.sd_unet_secondary not in (None, 'Default', 'None')
     reset_te = shared.opts.sd_text_encoder not in (None, 'Default', 'None')
-    if op == 'model' and sd_model is not None and changed_checkpoint and (reset_unet or reset_te):
+    if op == 'model' and sd_model is not None and changed_checkpoint and (reset_unet or reset_unet_secondary or reset_te):
         # compare detected model type, not pipeline class: custom-loader arches (e.g. Krea2) load as a
         # concrete class but detect as generic DiffusionPipeline, so a class compare would falsely reset
         # across same-arch checkpoints (Base vs Turbo). detect both sides so the comparison is symmetric.
@@ -1490,6 +1491,10 @@ def reload_model_weights(sd_model=None, info: CheckpointInfo | None = None, op='
                 log.info(f'Load model: type="{old_type}" changed="{new_type}" unet="{shared.opts.sd_unet}" set to default')
                 shared.opts.data["sd_unet"] = 'Default'
                 sd_unet.loaded_unet = None
+            if reset_unet_secondary:
+                log.info(f'Load model: type="{old_type}" changed="{new_type}" unet_secondary="{shared.opts.sd_unet_secondary}" set to default')
+                shared.opts.data["sd_unet_secondary"] = 'Default'
+                sd_unet.loaded_unet_secondary = None
             if reset_te:
                 log.info(f'Load model: type="{old_type}" changed="{new_type}" te="{shared.opts.sd_text_encoder}" set to default')
                 shared.opts.data["sd_text_encoder"] = 'Default'
diff --git a/modules/sd_unet.py b/modules/sd_unet.py
index 7072bd019..890662be0 100644
--- a/modules/sd_unet.py
+++ b/modules/sd_unet.py
@@ -5,11 +5,14 @@ from modules.logger import log
 
 unet_dict = {}
 loaded_unet = None
+loaded_unet_secondary = None
 failed_unet = []
 debug = os.environ.get('SD_LOAD_DEBUG', None) is not None
 
 
 dit_models = ['Flux', 'StableDiffusion3', 'HiDream', 'Lumina2', 'Chroma', 'Wan', 'Qwen', 'Anima']
+# model types (shared.sd_model_type keyspace) the secondary UNET override applies to
+DUAL_TRANSFORMER_TYPES = ('ideogram4', 'wanai')
 
 
 def load_unet_sdxl_nunchaku(repo_id):
@@ -101,6 +104,35 @@ def load_unet(model, repo_id: str | None = None):
     devices.torch_gc()
 
 
+def load_unet_secondary(model): # pylint: disable=unused-argument
+    """Onchange handler for the secondary UNET override: a change means a
+    full reload; for single-transformer models the selection is stored and
+    applies on the next dual-transformer load.
+    """
+    global loaded_unet_secondary  # pylint: disable=global-statement
+    selected = shared.opts.sd_unet_secondary
+
+    if selected is None or selected in ('Default', 'None'):
+        if loaded_unet_secondary in (None, 'Default', 'None'):
+            return
+        log.info(f'Load module: type=UNet slot=secondary name="Default" (was="{loaded_unet_secondary}") reverting to base transformer')
+        loaded_unet_secondary = selected
+        sd_models.reload_model_weights(force=True)
+        return
+
+    if selected not in list(unet_dict):
+        log.error(f'Load module: type=UNet slot=secondary not found: {selected}')
+        return
+    if selected == loaded_unet_secondary or selected in failed_unet:
+        return
+    if shared.sd_model_type not in DUAL_TRANSFORMER_TYPES:
+        log.warning(f'Load module: type=UNet slot=secondary name="{selected}" stored: model type={shared.sd_model_type} has a single transformer, applies on next dual-transformer load')
+        return
+    loaded_unet_secondary = selected
+    sd_models.reload_model_weights(force=True)
+    devices.torch_gc()
+
+
 def refresh_unet_list():
     unet_dict.clear()
     for file in files_cache.list_files(shared.opts.unet_dir, ext_filter=[".safetensors", ".gguf", ".pth"]):
diff --git a/modules/shared_items.py b/modules/shared_items.py
index a8e8e55ec..4bef8c855 100644
--- a/modules/shared_items.py
+++ b/modules/shared_items.py
@@ -116,6 +116,12 @@ def refresh_unet_list():
     modules.sd_unet.refresh_unet_list()
 
 
+def sd_unet_secondary_visible():
+    import modules.sd_unet
+    from modules import shared
+    return shared.sd_model_type in modules.sd_unet.DUAL_TRANSFORMER_TYPES
+
+
 def sd_te_items():
     import modules.model_te
     predefined = ['Default']
diff --git a/modules/ui_definitions.py b/modules/ui_definitions.py
index 7d0ac016e..2075256c9 100644
--- a/modules/ui_definitions.py
+++ b/modules/ui_definitions.py
@@ -94,6 +94,7 @@ def create_settings(cmd_opts):
         "sd_model_checkpoint": OptionInfo(default_checkpoint, "Base model", DropdownEditable, lambda: {"choices": list_checkpoint_titles()}, refresh=refresh_checkpoints),
         "sd_model_refiner": OptionInfo('None', "Refiner model", gr.Dropdown, lambda: {"choices": ['None'] + list_checkpoint_titles()}, refresh=refresh_checkpoints),
         "sd_unet": OptionInfo("Default", "UNET model", gr.Dropdown, lambda: {"choices": shared_items.sd_unet_items()}, refresh=shared_items.refresh_unet_list),
+        "sd_unet_secondary": OptionInfo("Default", "UNET model secondary", gr.Dropdown, lambda: {"choices": shared_items.sd_unet_items(), "visible": shared_items.sd_unet_secondary_visible()}, refresh=shared_items.refresh_unet_list),
         "latent_history": OptionInfo(20, "Latent history size", gr.Slider, {"minimum": 0, "maximum": 100, "step": 1}),
 
         "advanced_sep": OptionInfo("<h2>Advanced Options</h2>", "", gr.HTML),
diff --git a/modules/ui_settings.py b/modules/ui_settings.py
index b89b0d335..a1048d520 100644
--- a/modules/ui_settings.py
+++ b/modules/ui_settings.py
@@ -10,9 +10,20 @@ ui_system_tabs = None # required for system-info
 dummy_component = gr.Textbox(visible=False, value='dummy')
 loadsave = ui_loadsave.UiLoadsave(shared.cmd_opts.ui_config)
 quicksettings_names = {x: i for i, x in enumerate(shared.opts.quicksettings_list) if x != 'quicksettings'}
+# companion settings render beside their parent wherever it lives:
+# quicksettings the parent and the companion follows, keeping its own visibility
+companion_settings = (('sd_unet', 'sd_unet_secondary'),)
+for parent_key, companion_key in companion_settings:
+    if parent_key in quicksettings_names and companion_key not in quicksettings_names:
+        quicksettings_names[companion_key] = quicksettings_names[parent_key] + 0.5
 quicksettings_list = []
 hidden_list = []
 components = []
+# settings with model-dependent visibility: their wrapper group (settings page) or
+# refresh button (quicksettings) is registered here so visibility pushes toggle the
+# whole control, not just the inner dropdown
+dynamic_visibility_keys = ('sd_unet_secondary',)
+dynamic_visibility: dict = {}
 
 
 def apply_setting(key, value):
@@ -76,11 +87,15 @@ def create_setting_component(key, is_quicksettings=False):
         dirtyable_setting = gr.Group(elem_classes="dirtyable", visible=args.get("visible", True))
         dirtyable_setting.__enter__()
         dirty_indicator = gr.Button("", elem_classes="modification-indicator", elem_id=f"modification_indicator_{key}")
+        if key in dynamic_visibility_keys:
+            dynamic_visibility.setdefault(key, []).append(dirtyable_setting)
 
     if info.refresh is not None:
         if is_quicksettings:
             res = comp(label=info.label, value=fun(), elem_id=elem_id, **args)
-            ui_common.create_refresh_button(res, info.refresh, info.component_args, f"settings_{key}_refresh")
+            refresh_button = ui_common.create_refresh_button(res, info.refresh, info.component_args, f"settings_{key}_refresh", visible=args.get("visible", True))
+            if key in dynamic_visibility_keys:
+                dynamic_visibility.setdefault(key, []).append(refresh_button)
         else:
             with gr.Row():
                 res = comp(label=info.label, value=fun(), elem_id=elem_id, **args)
@@ -202,7 +217,7 @@ def run_settings_single(value, key, progress=False, force=False):
     shared.opts.save(silent=True)
     if key == 'sd_text_encoder':
         sd_models.reload_text_encoder() # apply the change now; reloads the model for encoders with no in-place swap
-    if key not in ['sd_model_checkpoint', 'sd_model_refiner', 'sd_vae', 'sd_te', 'sd_unet'] or force:
+    if key not in ['sd_model_checkpoint', 'sd_model_refiner', 'sd_vae', 'sd_te', 'sd_unet', 'sd_unet_secondary'] or force:
         log.debug(f'Setting changed: {key}="{value}" progress={progress} force={force}')
     return get_value_for_setting(key), shared.opts.dumpjson()
 
@@ -267,6 +282,7 @@ def create_ui(disabled_tabs=None):
 
             with gr.Tabs(elem_id="settings"):
                 quicksettings_list.clear()
+                dynamic_visibility.clear()
                 for (section_id, section_text) in sections:
                     items = [item for item in shared.opts.data_labels.items() if item[1].section[0] == section_id] # find all items in this section
                     hidden = section_id is None or 'hidden' in section_id.lower() or 'hidden' in section_text.lower()
@@ -364,7 +380,7 @@ def create_quicksettings(interfaces):
         with gr.Row(elem_id="quicksettings", variant="compact"):
             quicksetting_components = []
             quicksetting_keys = []
-            for k, _item in sorted(quicksettings_list, key=lambda x: quicksettings_names.get(x[1], x[0])):
+            for k, _item in sorted(quicksettings_list, key=lambda x: quicksettings_names.get(x[0], 0)):
                 component = create_setting_component(k, is_quicksettings=True)
                 quicksetting_components.append(component)
                 quicksetting_keys.append(k)
@@ -394,10 +410,20 @@ def create_quicksettings(interfaces):
             gr.Audio(interactive=False, value=os.path.join(paths.script_path, shared.opts.notification_audio_path), elem_id="audio_notification", visible=False)
 
         def sync_checkpoint_components(value, progress=False, force=False):
-            # a checkpoint change can reset sd_unet / sd_text_encoder to Default (arch changed);
-            # push both back so the dropdowns reflect it, not just the stored option
+            # a checkpoint change can reset sd_unet / sd_unet_secondary / sd_text_encoder
+            # (arch changed); push the current values back to the dropdowns. The secondary
+            # dropdown and its dynamic_visibility companions also toggle visibility here,
+            # since get_value_for_setting strips 'visible'.
+            from modules import sd_unet, shared_items
             checkpoint_update, settings_text = run_settings_single(value, key='sd_model_checkpoint', progress=progress, force=force)
-            return checkpoint_update, get_value_for_setting('sd_unet'), get_value_for_setting('sd_text_encoder'), settings_text
+            secondary_visible = shared.sd_model_type in sd_unet.DUAL_TRANSFORMER_TYPES
+            secondary_update = gr.update(
+                value=shared.opts.sd_unet_secondary,
+                choices=shared_items.sd_unet_items(),
+                visible=secondary_visible,
+            )
+            companion_updates = [gr.update(visible=secondary_visible) for _ in dynamic_visibility.get('sd_unet_secondary', [])]
+            return checkpoint_update, get_value_for_setting('sd_unet'), secondary_update, *companion_updates, get_value_for_setting('sd_text_encoder'), settings_text
 
         for k, _item in quicksettings_list:
             component = shared.settings_components[k]
@@ -417,7 +443,7 @@ def create_quicksettings(interfaces):
             if k == 'sd_model_checkpoint':
                 def fn(value, progress=progress_flag):
                     return sync_checkpoint_components(value, progress=progress)
-                outputs = [component, shared.settings_components['sd_unet'], shared.settings_components['sd_text_encoder'], text_settings]
+                outputs = [component, shared.settings_components['sd_unet'], shared.settings_components['sd_unet_secondary'], *dynamic_visibility.get('sd_unet_secondary', []), shared.settings_components['sd_text_encoder'], text_settings]
             else:
                 def fn(value, k=k, progress=progress_flag):
                     return run_settings_single(value, key=k, progress=progress)
@@ -438,7 +464,7 @@ def create_quicksettings(interfaces):
             fn=sync_checkpoint_components_forced,
             _js="consumeDesiredCheckpointName",
             inputs=[shared.settings_components['sd_model_checkpoint'], dummy_component],
-            outputs=[shared.settings_components['sd_model_checkpoint'], shared.settings_components['sd_unet'], shared.settings_components['sd_text_encoder'], text_settings],
+            outputs=[shared.settings_components['sd_model_checkpoint'], shared.settings_components['sd_unet'], shared.settings_components['sd_unet_secondary'], *dynamic_visibility.get('sd_unet_secondary', []), shared.settings_components['sd_text_encoder'], text_settings],
         )
         button_set_refiner = gr.Button('Change refiner', elem_id='change_refiner', visible=False)
         button_set_refiner.click(
diff --git a/pipelines/generic_transformer.py b/pipelines/generic_transformer.py
index 99b77a716..9de674781 100644
--- a/pipelines/generic_transformer.py
+++ b/pipelines/generic_transformer.py
@@ -21,10 +21,16 @@ def load_transformer(
         modules_dtype_dict=None,
         use_safetensors=True,
         native_spec=None,
+        override_slot='primary',
         **kwargs):
 
     """Load a DiT transformer from the base repo, or from a user-selected
-    single file when the UNET dropdown (``shared.opts.sd_unet``) is set.
+    single file when the slot's UNET override dropdown is set.
+
+    ``override_slot`` selects which dropdown this call consumes: ``'primary'``
+    reads ``shared.opts.sd_unet``, ``'secondary'`` reads
+    ``shared.opts.sd_unet_secondary`` (dual-transformer arches give each
+    transformer its own slot).
 
     With ``native_spec`` set and a .safetensors override selected, dispatches
     to :func:`pipelines.native_transformer.load`. Without a spec, a single-file
@@ -73,12 +79,19 @@ def load_transformer(
         fallback = True
 
         from modules import sd_unet
-        if shared.opts.sd_unet is not None and shared.opts.sd_unet != 'Default':
-            if shared.opts.sd_unet not in list(sd_unet.unet_dict):
-                log.error(f'Load module: type=transformer file="{shared.opts.sd_unet}" not found')
-            elif os.path.exists(sd_unet.unet_dict[shared.opts.sd_unet]):
-                local_file = sd_unet.unet_dict[shared.opts.sd_unet]
-                override_name = shared.opts.sd_unet
+        if override_slot == 'primary':
+            override_opt, tracker_attr = 'sd_unet', 'loaded_unet'
+        elif override_slot == 'secondary':
+            override_opt, tracker_attr = 'sd_unet_secondary', 'loaded_unet_secondary'
+        else:
+            raise ValueError(f'load_transformer: unknown override_slot={override_slot}')
+        selected = getattr(shared.opts, override_opt, None)
+        if selected is not None and selected != 'Default':
+            if selected not in list(sd_unet.unet_dict):
+                log.error(f'Load module: type=transformer slot={override_slot} file="{selected}" not found')
+            elif os.path.exists(sd_unet.unet_dict[selected]):
+                local_file = sd_unet.unet_dict[selected]
+                override_name = selected
 
         if repo_id.startswith(shared.opts.ckpt_dir) and os.path.exists(repo_id):
             log.error(f'Load model: transformer="{repo_id}" is incorrectly placed in the checkpoints folder')
@@ -120,8 +133,8 @@ def load_transformer(
                 log.warning(f'Load model: transformer="{local_file}" override incompatible with cls={cls_name.__name__} ({e})')
                 if fallback:
                     log.warning(f'Load model: transformer="{local_file}" ignoring override and loading base transformer')
-                    shared.opts.data['sd_unet'] = 'Default'
-                    sd_unet.loaded_unet = None
+                    shared.opts.data[override_opt] = 'Default'
+                    setattr(sd_unet, tracker_attr, None)
                     transformer = load_from_repo()
 
         # 3. load safetensors with diffusers loader
@@ -144,10 +157,10 @@ def load_transformer(
         else:
             transformer = load_from_repo()
 
-        # mark the dropdown selection as loaded so the sd_unet onchange callback
+        # mark the dropdown selection as loaded so the slot's onchange callback
         # does not force a redundant full reload for an already-consumed override
-        if transformer is not None and override_name is not None and shared.opts.sd_unet == override_name:
-            sd_unet.loaded_unet = override_name
+        if transformer is not None and override_name is not None and getattr(shared.opts, override_opt, None) == override_name:
+            setattr(sd_unet, tracker_attr, override_name)
 
         sd_models.allow_post_quant = False # we already handled it
         if shared.opts.diffusers_offload_mode != 'none' and transformer is not None:
@@ -173,12 +186,15 @@ def load_transformer(
         log.debug(f'Load model: transformer="{repo_id}" quant="{quant_type}" size={module_size:.3f} params={param_num:.3f} memory={module_memory}')
 
     try:
-        actual_dtype = transformer.dtype
-        if isinstance(actual_dtype, torch.dtype) and isinstance(dtype, torch.dtype) and actual_dtype != dtype:
-            force = shared.opts.force_dtype
-            log.warning(f'Load model: transformer="{repo_id}" dtype desired={dtype} actual={actual_dtype} force={force}')
-            if force:
-                transformer = transformer.to(dtype)
+        # quantized models legitimately report the storage dtype (e.g. fp8 comfy_quant
+        # adopted via SDNQ); the compute dtype lives in the dequantizers, not the params
+        if getattr(transformer, 'quantization_config', None) is None:
+            actual_dtype = transformer.dtype
+            if isinstance(actual_dtype, torch.dtype) and isinstance(dtype, torch.dtype) and actual_dtype != dtype:
+                force = shared.opts.force_dtype
+                log.warning(f'Load model: transformer="{repo_id}" dtype desired={dtype} actual={actual_dtype} force={force}')
+                if force:
+                    transformer = transformer.to(dtype)
     except Exception:
         pass
 
diff --git a/pipelines/ideogram/__init__.py b/pipelines/ideogram/__init__.py
new file mode 100644
index 000000000..f0b6585f7
--- /dev/null
+++ b/pipelines/ideogram/__init__.py
@@ -0,0 +1,62 @@
+"""Ideogram 4 native loader spec.
+
+Kept import-light: only the converter and spec live here so the native
+loader can import them without pulling the pipeline or the qwen patch.
+"""
+
+import re
+
+import torch
+import diffusers
+
+from pipelines.native_transformer import TransformerSpec
+
+
+QKV_TARGETS = ("to_q", "to_k", "to_v")
+QKV_RE = re.compile(r"^(layers\.\d+\.attention)\.qkv\.(.+)$")
+OUT_RE = re.compile(r"^(layers\.\d+\.attention)\.o\.(.+)$")
+
+
+def convert_ideogram4_transformer_checkpoint(state_dict: dict, **kwargs) -> dict:  # pylint: disable=unused-argument
+    """Fused community layout to ``Ideogram4Transformer2DModel`` layout.
+
+    ``layers.N.attention.qkv.<suffix>`` splits into ``to_q/to_k/to_v.<suffix>``:
+    row-stacked tensors (weight, row-wise scale, bias) are dim-0 sliced into
+    thirds, non-row-stacked sidecars (markers, scalar scales) copied verbatim
+    to all three. ``attention.o.<suffix>`` renames to ``attention.to_out.0.<suffix>``,
+    everything else passes through. Returns a new dict; the input (which may
+    be the cached state dict) is not mutated.
+    """
+    converted: dict = {}
+    for key, value in state_dict.items():
+        fused_match = QKV_RE.match(key)
+        if fused_match is not None:
+            prefix, suffix = fused_match.group(1), fused_match.group(2)
+            fused_weight = state_dict.get(f"{prefix}.qkv.weight")
+            fused_rows = fused_weight.shape[0] if torch.is_tensor(fused_weight) and fused_weight.ndim >= 1 else None
+            row_stacked = (
+                suffix != "comfy_quant"
+                and torch.is_tensor(value) and value.ndim >= 1
+                and fused_rows is not None and value.shape[0] == fused_rows and fused_rows % 3 == 0
+            )
+            if row_stacked:
+                third = fused_rows // 3
+                for i, target in enumerate(QKV_TARGETS):
+                    converted[f"{prefix}.{target}.{suffix}"] = value[i * third:(i + 1) * third]
+            else:
+                for target in QKV_TARGETS:
+                    converted[f"{prefix}.{target}.{suffix}"] = value
+            continue
+        out_match = OUT_RE.match(key)
+        if out_match is not None:
+            converted[f"{out_match.group(1)}.to_out.0.{out_match.group(2)}"] = value
+            continue
+        converted[key] = value
+    return converted
+
+
+IDEOGRAM4_SPEC = TransformerSpec(
+    cls=diffusers.Ideogram4Transformer2DModel,
+    converter=convert_ideogram4_transformer_checkpoint,
+    converter_handles_quant=True,
+)
diff --git a/pipelines/model_ideogram4.py b/pipelines/model_ideogram4.py
index cbb09e5d3..3dcdac0c1 100644
--- a/pipelines/model_ideogram4.py
+++ b/pipelines/model_ideogram4.py
@@ -1,3 +1,5 @@
+import dataclasses
+
 import diffusers
 import transformers
 from modules import shared, devices, sd_models, model_quant, sd_hijack_te, sd_hijack_vae
@@ -41,11 +43,16 @@ def load_ideogram4(checkpoint_info, diffusers_load_config=None):
     if repo_id is None or repo_id.lower() == 'none':
         return None
 
+    from pipelines.ideogram import IDEOGRAM4_SPEC
     transformer_cls = diffusers.Ideogram4Transformer2DModel
 
-    transformer = generic.load_transformer(repo_id, cls_name=transformer_cls, subfolder="transformer", load_config=diffusers_load_config)
+    transformer = generic.load_transformer(repo_id, cls_name=transformer_cls, subfolder="transformer", load_config=diffusers_load_config, native_spec=IDEOGRAM4_SPEC)
     if shared.opts.model_ideogram4_enable_cg:
-        unconditional_transformer = generic.load_transformer(repo_id, cls_name=transformer_cls, subfolder="unconditional_transformer", load_config=diffusers_load_config)
+        # the spec subfolder swap makes an unconditional override fetch its config from the matching subfolder
+        unconditional_transformer = generic.load_transformer(
+            repo_id, cls_name=transformer_cls, subfolder="unconditional_transformer", load_config=diffusers_load_config,
+            native_spec=dataclasses.replace(IDEOGRAM4_SPEC, subfolder="unconditional_transformer"), override_slot='secondary',
+        )
     else:
         unconditional_transformer = None
     text_encoder = generic.load_text_encoder(repo_id, cls_name=transformers.Qwen3VLModel, load_config=diffusers_load_config)
diff --git a/pipelines/model_wanai.py b/pipelines/model_wanai.py
index 2a7a421ea..9a9a1bdda 100644
--- a/pipelines/model_wanai.py
+++ b/pipelines/model_wanai.py
@@ -42,7 +42,7 @@ def load_wan(checkpoint_info, diffusers_load_config=None):
             boundary_ratio = 1000.0
         elif shared.opts.model_wan_stage == 'combined' or shared.opts.model_wan_stage == 'both':
             transformer = generic.load_transformer(repo_id, cls_name=transformer_cls, load_config=diffusers_load_config, subfolder='transformer')
-            transformer_2 = generic.load_transformer(repo_id, cls_name=transformer_cls, load_config=diffusers_load_config, subfolder='transformer_2')
+            transformer_2 = generic.load_transformer(repo_id, cls_name=transformer_cls, load_config=diffusers_load_config, subfolder='transformer_2', override_slot='secondary')
             # load with the checkpoint's boundary; the slider override is applied at runtime in set_pipeline_args
             boundary_ratio = None
         else:
diff --git a/pipelines/native_transformer.py b/pipelines/native_transformer.py
index ab3a0e42b..2fbf3f797 100644
--- a/pipelines/native_transformer.py
+++ b/pipelines/native_transformer.py
@@ -128,6 +128,10 @@ class TransformerSpec:
     VAE) that all-in-one exports bundle alongside the transformer; their keys
     are dropped before prefix detection rather than treated as a malformed
     file.
+
+    ``converter_handles_quant`` runs the converter before comfy_quant
+    detection; such converters must translate marker/scale sidecar keys along
+    with the weights. Float-oriented converters keep the default.
     """
 
     cls: type
@@ -135,6 +139,7 @@ class TransformerSpec:
     prefixes: tuple[str, ...] = DEFAULT_PREFIXES
     ignored_prefixes: tuple[str, ...] = DEFAULT_IGNORED_PREFIXES
     converter: Callable[[dict], dict] | None = None
+    converter_handles_quant: bool = False
     siblings: dict[str, SiblingSpec] = field(default_factory=dict)
     acceptable_missing: tuple[str, ...] = DEFAULT_ACCEPTABLE_MISSING
     zero_init_missing: tuple[str, ...] = ()
@@ -298,6 +303,7 @@ def load(
         dtype=effective_dtype,
         modules_to_not_convert=modules_to_not_convert,
         modules_dtype_dict=modules_dtype_dict,
+        converter_handles_quant=spec.converter_handles_quant,
         **kwargs,
     )
     del transformer_sd
@@ -422,9 +428,9 @@ def check_forbidden_markers(
 
 
 def detect_comfy_quant(state_dict: dict, type_name: str) -> tuple[set[str], str] | None:
-    """Detect ComfyUI ``comfy_quant`` pre-quantized layers in a state dict.
+    """Detect ``comfy_quant`` pre-quantized layers in a state dict.
 
-    ComfyUI's quantized checkpoints mark each quantized layer with a
+    ComfyUI-format quantized checkpoints mark each quantized layer with a
     ``<name>.comfy_quant`` uint8 tensor whose bytes are a JSON object naming
     the storage format, alongside a ``<name>.weight_scale`` tensor. Returns
     the set of marked module names and the format string, or ``None`` when no
@@ -646,28 +652,17 @@ def build_component_prequantized(
     **kwargs,
 ) -> object:
     """Build a component from a comfy_quant pre-quantized state dict, mapping
-    the marked layers onto SDNQ quantized layers without dequantizing.
+    the marked layers onto SDNQ layers without dequantizing.
 
-    The supported comfy formats (``int8_tensorwise``, ``float8_e4m3fn``) are
-    strict subsets of SDNQ's symmetric quantization for the corresponding
-    weights dtype: same storage layout (unpacked 8-bit ``[out, in]``), same
-    dequant math (``weight * scale``, no zero point), so the file's tensors
-    are adopted bit-exact. The model is built under ``init_empty_weights``
-    and each marked Linear is swapped for an SDNQ wrapper with per-tensor
-    dequant geometry (``group_size=-1``, scalar scale); the file dictates
-    which layers are quantized, independent of the user's quantization
-    settings. Weights load through ``SDNQQuantizer``'s pre-quantized path,
-    which preserves the quantized weight dtype and the fp32 scale (unlike
-    :func:`build_component_quantized`, floating-point SDNQ params are
-    deliberately not cast to the target dtype).
-
-    Layers are assembled in canonical dequant layout first;
-    ``apply_sdnq_options_to_model`` then enables quantized matmul per the
-    user's settings (transposing eligible layers), matching the order used by
+    The supported formats are subsets of SDNQ's symmetric quantization: same
+    storage layout (unpacked 8-bit ``[out, in]``), same dequant math
+    (``weight * scale``, no zero point), so tensors are adopted bit-exact.
+    The file dictates which layers are quantized, independent of the user's
+    quantization settings, and floating-point SDNQ params are not cast to the
+    target dtype (the fp32 scales must survive). Layers are assembled in
+    canonical dequant layout; ``apply_sdnq_options_to_model`` then applies
+    the user's quantized-matmul settings, matching
     ``modules.sdnq.loader.load_sdnq_model``.
-
-    Caller is responsible for prefix stripping; the state dict arrives with
-    its comfy marker keys intact and is remapped here.
     """
     import rich.progress as rp
     from accelerate import init_empty_weights
@@ -803,6 +798,22 @@ def build_component_prequantized(
     return component
 
 
+def apply_converter(converter: Callable[[dict], dict], state_dict: dict, cls: type, component_name: str) -> dict:
+    """Run a spec converter, wrapping any failure as
+    :class:`OverrideArchMismatch` (with the original chained) so a wrong-arch
+    file degrades to the base-repo fallback instead of a raw converter crash.
+    """
+    log.debug(f'Load model: transformer=native {component_name} converter={converter.__name__} keys={len(state_dict)}')
+    try:
+        return converter(state_dict)
+    except Exception as e:
+        raise OverrideArchMismatch(
+            f"Load model: type={cls.__name__} native_transformer converter "
+            f"{converter.__name__} rejected the override ({type(e).__name__}: {e}); "
+            f"file does not look like a {cls.__name__} checkpoint"
+        ) from e
+
+
 def build_component(
     *,
     component_name: str,
@@ -817,21 +828,21 @@ def build_component(
     dtype=None,
     modules_to_not_convert: list | None = None,
     modules_dtype_dict: dict | None = None,
+    converter_handles_quant: bool = False,
     **kwargs,
 ) -> object:
     """Convert (if needed), instantiate, load weights, dtype-cast, quantize,
     and offload-place a single component. Raises on any hard failure.
 
-    Transformer state dicts carrying ComfyUI ``comfy_quant`` markers are
-    dispatched to :func:`build_component_prequantized`, which adopts the
-    file's int8 tensors as SDNQ layers regardless of quantization settings
-    (the converter and ``quant_args`` are bypassed: the file is already
-    quantized). For the transformer component under SDNQ, the per-tensor
-    pre-mode path in :func:`build_component_quantized` is used so
-    quantization is applied in flight (one layer's worth of bf16 in memory
-    at a time). All other cases (siblings, non-quantized loads,
-    NVIDIAModelOptConfig, layerwise quant) go through the standard
-    load_state_dict + post-quantize path.
+    Transformer state dicts carrying ``comfy_quant`` markers dispatch
+    to :func:`build_component_prequantized` (``quant_args`` are bypassed: the
+    file is already quantized); a ``converter_handles_quant`` converter runs
+    before that detection, float-oriented converters after it. Under SDNQ the
+    transformer uses the per-tensor pre-mode path in
+    :func:`build_component_quantized` so quantization is applied in flight.
+    All other cases (siblings, non-quantized loads, NVIDIAModelOptConfig,
+    layerwise quant) go through the standard load_state_dict + post-quantize
+    path.
 
     ``dtype`` overrides ``devices.dtype`` when supplied; otherwise the global
     default is used. ``modules_to_not_convert`` and ``modules_dtype_dict``
@@ -840,6 +851,10 @@ def build_component(
     reach ``cls.from_config`` for both construction paths.
     """
     try:
+        if converter is not None and converter_handles_quant and component_name == "transformer":
+            state_dict = apply_converter(converter, state_dict, cls, component_name)
+            converter = None  # consumed; must not run again on the non-comfy path below
+
         comfy_quant = detect_comfy_quant(state_dict, cls.__name__) if component_name == "transformer" else None
         if comfy_quant is not None:
             marked_names, comfy_format = comfy_quant
@@ -863,15 +878,7 @@ def build_component(
             return component
 
         if converter is not None:
-            log.debug(f'Load model: transformer=native {component_name} converter={converter.__name__} keys={len(state_dict)}')
-            try:
-                sd = converter(state_dict)
-            except Exception as e:
-                raise OverrideArchMismatch(
-                    f"Load model: type={cls.__name__} native_transformer converter "
-                    f"{converter.__name__} rejected the override ({type(e).__name__}: {e}); "
-                    f"file does not look like a {cls.__name__} checkpoint"
-                ) from e
+            sd = apply_converter(converter, state_dict, cls, component_name)
         else:
             sd = state_dict
 
diff --git a/test/test-native-transformer.py b/test/test-native-transformer.py
index 616fc8c5a..a8cd14687 100644
--- a/test/test-native-transformer.py
+++ b/test/test-native-transformer.py
@@ -8,7 +8,7 @@ Covers the pure helpers that own per-arch knob handling:
 - ``strip_prefix`` for single/multi prefix detection and mixed-prefix rejection
 - ``partition_siblings`` for inline-sibling key partitioning
 - ``check_forbidden_markers`` for structural-mismatch rejection
-- ``detect_comfy_quant`` for ComfyUI comfy_quant marker detection and format gating
+- ``detect_comfy_quant`` for comfy_quant marker detection and format gating
 - ``remap_comfy_quant`` for comfy_quant -> SDNQ key translation
 - ``is_noop_converter`` for diffusers no-op lambda detection
 - ``validate_state_dict_load`` for unexpected / missing key handling
@@ -954,6 +954,104 @@ def test_load_converter_crash_raises_mismatch():
             os.unlink(path)
 
 
+# ============================================================
+# Ideogram 4 converter (fused community layout -> diffusers layout)
+# ============================================================
+
+def ideogram_converter():
+    from pipelines.ideogram import convert_ideogram4_transformer_checkpoint
+    return convert_ideogram4_transformer_checkpoint
+
+
+def test_ideogram4_converter_splits_fused_qkv_weight():
+    convert = ideogram_converter()
+    fused = torch.arange(48, dtype=torch.float32).reshape(12, 4)
+    out = convert({'layers.0.attention.qkv.weight': fused})
+    assert set(out.keys()) == {f'layers.0.attention.{n}.weight' for n in ('to_q', 'to_k', 'to_v')}
+    assert torch.equal(out['layers.0.attention.to_q.weight'], fused[0:4])
+    assert torch.equal(out['layers.0.attention.to_k.weight'], fused[4:8])
+    assert torch.equal(out['layers.0.attention.to_v.weight'], fused[8:12])
+
+
+def test_ideogram4_converter_splits_rowwise_scale():
+    convert = ideogram_converter()
+    fused = torch.zeros((12, 4), dtype=torch.int8)
+    scale = torch.arange(12, dtype=torch.float32).reshape(12, 1)
+    out = convert({'layers.3.attention.qkv.weight': fused, 'layers.3.attention.qkv.weight_scale': scale})
+    assert torch.equal(out['layers.3.attention.to_q.weight_scale'], scale[0:4])
+    assert torch.equal(out['layers.3.attention.to_v.weight_scale'], scale[8:12])
+    assert out['layers.3.attention.to_k.weight_scale'].shape == (4, 1)
+
+
+def test_ideogram4_converter_scalar_scale_copied_not_sliced():
+    convert = ideogram_converter()
+    fused = torch.zeros((12, 4), dtype=torch.int8)
+    scale = torch.tensor(0.5)
+    out = convert({'layers.0.attention.qkv.weight': fused, 'layers.0.attention.qkv.weight_scale': scale})
+    for name in ('to_q', 'to_k', 'to_v'):
+        assert out[f'layers.0.attention.{name}.weight_scale'] is scale
+
+
+def test_ideogram4_converter_duplicates_marker():
+    convert = ideogram_converter()
+    fused = torch.zeros((12, 4), dtype=torch.int8)
+    marker = comfy_marker('int8_tensorwise')
+    out = convert({'layers.0.attention.qkv.weight': fused, 'layers.0.attention.qkv.comfy_quant': marker})
+    for name in ('to_q', 'to_k', 'to_v'):
+        assert out[f'layers.0.attention.{name}.comfy_quant'] is marker
+
+
+def test_ideogram4_converter_renames_o_with_sidecars():
+    convert = ideogram_converter()
+    sd = {
+        'layers.5.attention.o.weight': torch.zeros((4, 4), dtype=torch.int8),
+        'layers.5.attention.o.weight_scale': torch.tensor(1.0),
+        'layers.5.attention.o.comfy_quant': comfy_marker('int8_tensorwise'),
+    }
+    out = convert(sd)
+    assert set(out.keys()) == {
+        'layers.5.attention.to_out.0.weight',
+        'layers.5.attention.to_out.0.weight_scale',
+        'layers.5.attention.to_out.0.comfy_quant',
+    }
+
+
+def test_ideogram4_converter_passthrough():
+    convert = ideogram_converter()
+    sd = {
+        'input_proj.weight': torch.zeros(4),
+        'llm_cond_proj.weight': torch.zeros(4),
+        'layers.0.feed_forward.w1.weight': torch.zeros(4),
+        'layers.0.attention.norm_q.weight': torch.zeros(4),
+        'layers.0.adaln_modulation.bias': torch.zeros(4),
+        'final_layer.linear.weight': torch.zeros(4),
+    }
+    out = convert(sd)
+    assert set(out.keys()) == set(sd.keys())
+    for k, v in sd.items():
+        assert out[k] is v
+
+
+def test_ideogram4_converter_defensive_bias_split():
+    convert = ideogram_converter()
+    fused = torch.zeros((12, 4), dtype=torch.float32)
+    bias = torch.arange(12, dtype=torch.float32)
+    out = convert({'layers.0.attention.qkv.weight': fused, 'layers.0.attention.qkv.bias': bias})
+    assert torch.equal(out['layers.0.attention.to_k.bias'], bias[4:8])
+
+
+def test_ideogram4_converter_does_not_mutate_input():
+    convert = ideogram_converter()
+    sd = {
+        'layers.0.attention.qkv.weight': torch.zeros((12, 4)),
+        'layers.0.attention.o.weight': torch.zeros((4, 4)),
+        'input_proj.weight': torch.zeros(4),
+    }
+    keys_before = set(sd.keys())
+    convert(sd)
+    assert set(sd.keys()) == keys_before
+
+
 # ============================================================
 # Integration: comfy_quant pre-quantized load
 # ============================================================
@@ -1238,6 +1336,204 @@ def test_load_transformer_syncs_loaded_unet():
             os.unlink(path)
 
 
+class MockFusedAttention(torch.nn.Module):
+    """Split-attention module tree matching Ideogram4Transformer2DModel's
+    naming (to_q/to_k/to_v + to_out ModuleList), fed by fused checkpoints."""
+
+    def __init__(self, dim: int):
+        super().__init__()
+        self.to_q = torch.nn.Linear(dim, dim, bias=False)
+        self.to_k = torch.nn.Linear(dim, dim, bias=False)
+        self.to_v = torch.nn.Linear(dim, dim, bias=False)
+        self.to_out = torch.nn.ModuleList([torch.nn.Linear(dim, dim, bias=False), torch.nn.Dropout(0.0)])
+
+
+class MockFusedBlock(torch.nn.Module):
+    def __init__(self, dim: int):
+        super().__init__()
+        self.attention = MockFusedAttention(dim)
+
+
+class MockFusedTransformer(torch.nn.Module):
+    @classmethod
+    def from_config(cls, config: dict, **kwargs) -> 'MockFusedTransformer':
+        return cls(dim=config['dim'])
+
+    def __init__(self, dim: int):
+        super().__init__()
+        self.layers = torch.nn.ModuleList([MockFusedBlock(dim)])
+        self.input_proj = torch.nn.Linear(dim, dim)
+
+
+def fused_spec():
+    from pipelines.ideogram import convert_ideogram4_transformer_checkpoint
+    return nt.TransformerSpec(
+        cls=MockFusedTransformer,
+        converter=convert_ideogram4_transformer_checkpoint,
+        converter_handles_quant=True,
+    )
+
+
+def fused_fixture(dim: int, quantized: bool = True) -> dict:
+    if quantized:
+        qkv = torch.randint(-128, 127, (3 * dim, dim), dtype=torch.int8)
+    else:
+        qkv = torch.randn(3 * dim, dim, dtype=torch.float16)
+    raw = {
+        'model.diffusion_model.layers.0.attention.qkv.weight': qkv,
+        'model.diffusion_model.layers.0.attention.o.weight': torch.randn(dim, dim, dtype=torch.float16),
+        'model.diffusion_model.input_proj.weight': torch.randn(dim, dim, dtype=torch.float16),
+        'model.diffusion_model.input_proj.bias': torch.zeros(dim, dtype=torch.float16),
+    }
+    if quantized:
+        raw['model.diffusion_model.layers.0.attention.qkv.weight_scale'] = torch.rand(3 * dim, 1, dtype=torch.float32)
+        raw['model.diffusion_model.layers.0.attention.qkv.comfy_quant'] = comfy_marker('int8_tensorwise')
+    return raw
+
+
+def test_load_fused_comfy_end_to_end():
+    """Quant-aware converter + comfy adoption: fused int8 qkv with row-wise
+    scales lands as three SDNQ linears holding the exact row slices."""
+    fd, path = tempfile.mkstemp(suffix='.safetensors')
+    try:
+        dim = 8
+        raw = fused_fixture(dim, quantized=True)
+        write_fixture(raw, fd, path)
+        with ComfyTestEnv(dim):
+            transformer, _ = nt.load(local_file=path, repo_id='fake/repo', spec=fused_spec(), diffusers_cfg={}, dtype=torch.float32)
+
+        attn = transformer.layers[0].attention
+        fused_w = raw['model.diffusion_model.layers.0.attention.qkv.weight']
+        fused_s = raw['model.diffusion_model.layers.0.attention.qkv.weight_scale']
+        for i, name in enumerate(('to_q', 'to_k', 'to_v')):
+            layer = getattr(attn, name)
+            assert layer.__class__.__name__ == 'SDNQLinear', f'{name} is {layer.__class__.__name__}'
+            assert layer.weight.dtype == torch.int8
+            assert torch.equal(layer.weight.detach().cpu(), fused_w[i * dim:(i + 1) * dim])
+            assert tuple(layer.scale.shape) == (dim, 1), f'{name} scale shape {layer.scale.shape}'
+            assert torch.equal(layer.scale.detach().cpu(), fused_s[i * dim:(i + 1) * dim])
+            expected = fused_w[i * dim:(i + 1) * dim].float() * fused_s[i * dim:(i + 1) * dim]
+            dequantized = layer.sdnq_dequantizer(layer.weight, layer.scale, zero_point=None, svd_up=None, svd_down=None)
+            assert torch.equal(dequantized.detach().cpu(), expected)
+        # unmarked o.weight passes through the rename as a plain Linear
+        assert attn.to_out[0].__class__ is torch.nn.Linear
+        assert torch.allclose(attn.to_out[0].weight.detach().cpu(), raw['model.diffusion_model.layers.0.attention.o.weight'].float())
+        assert transformer.input_proj.__class__ is torch.nn.Linear
+    finally:
+        if os.path.exists(path):
+            os.unlink(path)
+
+
+def test_load_fused_bf16_end_to_end():
+    """Converter-first on a plain float fused file: no markers, standard load
+    path, split weights land on the class-native linears."""
+    fd, path = tempfile.mkstemp(suffix='.safetensors')
+    try:
+        dim = 8
+        raw = fused_fixture(dim, quantized=False)
+        write_fixture(raw, fd, path)
+        with ComfyTestEnv(dim):
+            transformer, _ = nt.load(local_file=path, repo_id='fake/repo', spec=fused_spec(), diffusers_cfg={}, dtype=torch.float32)
+
+        attn = transformer.layers[0].attention
+        fused_w = raw['model.diffusion_model.layers.0.attention.qkv.weight']
+        for i, name in enumerate(('to_q', 'to_k', 'to_v')):
+            layer = getattr(attn, name)
+            assert layer.__class__ is torch.nn.Linear
+            assert torch.allclose(layer.weight.detach().cpu(), fused_w[i * dim:(i + 1) * dim].float())
+    finally:
+        if os.path.exists(path):
+            os.unlink(path)
+
+
+def test_load_fused_convrot_falls_back():
+    """The one real Ideogram 4 civitai file is convrot-flagged: conversion
+    succeeds, then detection rejects it into the base-repo fallback."""
+    import json as json_mod
+    fd, path = tempfile.mkstemp(suffix='.safetensors')
+    try:
+        dim = 8
+        raw = fused_fixture(dim, quantized=True)
+        payload = json_mod.dumps({'format': 'int8_tensorwise', 'convrot': True, 'convrot_groupsize': 256, 'per_row': True})
+        raw['model.diffusion_model.layers.0.attention.qkv.comfy_quant'] = torch.tensor(list(payload.encode()), dtype=torch.uint8)
+        write_fixture(raw, fd, path)
+        with ComfyTestEnv(dim):
+            raised = False
+            try:
+                nt.load(local_file=path, repo_id='fake/repo', spec=fused_spec(), diffusers_cfg={})
+            except nt.OverrideArchMismatch as e:
+                raised = True
+                assert 'convrot' in str(e)
+            assert raised, 'expected OverrideArchMismatch'
+    finally:
+        if os.path.exists(path):
+            os.unlink(path)
+
+
+def test_build_component_comfy_skips_converter_when_not_quant_aware():
+    """With converter_handles_quant=False (the default for every other arch),
+    a comfy state dict must reach the prequantized path without the converter
+    ever running; a crashing converter proves it was not invoked."""
+    dim = 8
+    raw = comfy_fixture(dim)
+    sd = {k[len('model.diffusion_model.'):]: v for k, v in raw.items()}
+    with ComfyTestEnv(dim):
+        component = nt.build_component(
+            component_name='transformer',
+            state_dict=sd,
+            config={'dim': dim},
+            cls=MockMiniTransformer,
+            converter=crashing_converter,
+            acceptable_missing=('rope.',),
+            quant_args={},
+            quant_type='SDNQConfig',
+            dtype=torch.float32,
+        )
+    assert component.in_proj.__class__.__name__ == 'SDNQLinear'
+
+
+def test_load_transformer_secondary_slot_syncs_tracker():
+    """The secondary slot consumes sd_unet_secondary and syncs its own
+    tracker without touching the primary slot."""
+    from modules import sd_unet, shared
+    from pipelines import generic_transformer as gt
+
+    fd, path = tempfile.mkstemp(suffix='.safetensors')
+    dim = 8
+    raw = {
+        'model.diffusion_model.in_proj.weight': torch.randn(dim, dim),
+        'model.diffusion_model.in_proj.bias': torch.zeros(dim),
+        'model.diffusion_model.out_proj.weight': torch.randn(dim, dim),
+        'model.diffusion_model.out_proj.bias': torch.zeros(dim),
+    }
+    write_fixture(raw, fd, path)
+
+    orig_primary_opt = shared.opts.sd_unet
+    orig_secondary_opt = shared.opts.sd_unet_secondary
+    orig_primary = sd_unet.loaded_unet
+    orig_secondary = sd_unet.loaded_unet_secondary
+    sd_unet.unet_dict['mock-unet-2'] = path
+    shared.opts.data['sd_unet'] = 'Default'
+    shared.opts.data['sd_unet_secondary'] = 'mock-unet-2'
+    sd_unet.loaded_unet = None
+    sd_unet.loaded_unet_secondary = None
+    try:
+        with ComfyTestEnv(dim):
+            spec = nt.TransformerSpec(cls=MockMiniTransformer)
+            transformer = gt.load_transformer('fake/repo', cls_name=MockMiniTransformer, native_spec=spec, override_slot='secondary')
+        assert transformer is not None
+        assert sd_unet.loaded_unet_secondary == 'mock-unet-2'
+        assert sd_unet.loaded_unet is None, 'primary tracker must stay untouched'
+    finally:
+        sd_unet.unet_dict.pop('mock-unet-2', None)
+        shared.opts.data['sd_unet'] = orig_primary_opt
+        shared.opts.data['sd_unet_secondary'] = orig_secondary_opt
+        sd_unet.loaded_unet = orig_primary
+        sd_unet.loaded_unet_secondary = orig_secondary
+        if os.path.exists(path):
+            os.unlink(path)
+
+
 def test_build_component_comfy_preempts_sdnq_fresh_quant():
     """When SDNQ on-load quant settings are active (quant_type=SDNQConfig), a
     comfy_quant file must still take the pre-quantized path: fresh quant of
@@ -1395,7 +1691,26 @@ def run_all():
         test_load_comfy_unsupported_format_raises_mismatch,
         test_load_comfy_marker_for_unknown_module_raises_mismatch,
         test_load_transformer_syncs_loaded_unet,
+        test_load_transformer_secondary_slot_syncs_tracker,
         test_build_component_comfy_preempts_sdnq_fresh_quant,
+        test_build_component_comfy_skips_converter_when_not_quant_aware,
+    ]:
+        run_test(cat, fn)
+
+    log.warning('=== ideogram4 converter / fused load ===')
+    cat = category('ideogram4')
+    for fn in [
+        test_ideogram4_converter_splits_fused_qkv_weight,
+        test_ideogram4_converter_splits_rowwise_scale,
+        test_ideogram4_converter_scalar_scale_copied_not_sliced,
+        test_ideogram4_converter_duplicates_marker,
+        test_ideogram4_converter_renames_o_with_sidecars,
+        test_ideogram4_converter_passthrough,
+        test_ideogram4_converter_defensive_bias_split,
+        test_ideogram4_converter_does_not_mutate_input,
+        test_load_fused_comfy_end_to_end,
+        test_load_fused_bf16_end_to_end,
+        test_load_fused_convrot_falls_back,
     ]:
         run_test(cat, fn)
 
diff --git a/ui/locale/locale_en.json b/ui/locale/locale_en.json
index 8ec96e8d4..21a90ce7b 100644
--- a/ui/locale/locale_en.json
+++ b/ui/locale/locale_en.json
@@ -1561,6 +1561,7 @@
     {"id":"","label":"Use spaces","localized":"","hint":"Replace underscores with spaces in tag output.<br>Some prompt systems prefer spaces between words (e.g., 'long hair') while others use underscores (e.g., 'long_hair').","ui":"caption"},
     {"id":"","label":"Username","localized":"","hint":"","ui":"component-8823"},
     {"id":"","label":"UNET model","localized":"","hint":"","ui":"settings_sd"},
+    {"id":"","label":"UNET model secondary","localized":"","hint":"Override for the second transformer of dual-transformer architectures:<br>- <b>Ideogram 4</b>: the unconditional transformer<br>- <b>Wan</b> combined stage: the second expert (transformer_2)<br><br>Shown only when the loaded model has a second transformer.<br>Default loads the component from the base model.","ui":"settings_sd"},
     {"id":"","label":"Use torch streams","localized":"","hint":"In <b>group</b> offload, uses CUDA streams to prefetch the next group while the current one runs, hiding transfer latency.<br>Faster, but uses more VRAM.<br><br>Applies only to <b>group</b> offload.<br><br>Disabled by default.","reload":"model","ui":"settings_offload"},
     {"id":"","label":"Use SVD quantization","localized":"","hint":"Adds a low-rank (SVDQuant) correction on top of SDNQ to recover accuracy lost at low bit widths, at the cost of extra size and compute.<br>Tuned by <b><i>SVD rank size</i></b> and <b><i>SVD steps</i></b>.<br><br>Disabled by default.","reload":"model","ui":"settings_quantization"},
     {"id":"","label":"Use Dynamic quantization","localized":"","hint":"Picks a per-layer weight type automatically instead of one type everywhere. Each layer starts at the <b><i>Quantization type</i></b> (the minimum) and steps up to higher precision until its error meets the <b><i>Dynamic loss threshold</i></b>.<br>Protects error-sensitive layers at the cost of a larger model and slower load.<br><br>Disabled by default.","reload":"model","ui":"settings_quantization"},
diff --git a/webui.py b/webui.py
index 92ebe6eff..480bb03ff 100644
--- a/webui.py
+++ b/webui.py
@@ -184,6 +184,7 @@ def load_model():
     shared.opts.onchange("sd_model_refiner", wrap_queued_call(lambda: modules.sd_models.reload_model_weights(op='refiner')), call=False)
     shared.opts.onchange("sd_vae", wrap_queued_call(lambda: modules.sd_vae.reload_vae_weights()), call=False)
     shared.opts.onchange("sd_unet", wrap_queued_call(lambda: modules.sd_unet.load_unet(shared.sd_model)), call=False)
+    shared.opts.onchange("sd_unet_secondary", wrap_queued_call(lambda: modules.sd_unet.load_unet_secondary(shared.sd_model)), call=False)
     shared.opts.onchange("sd_text_encoder", wrap_queued_call(lambda: modules.sd_models.reload_text_encoder()), call=False)
     shared.opts.onchange("temp_dir", modules.gr_tempdir.on_tmpdir_changed)
     timer.startup.record("onchange")